The optional maxclass= keyword specifies the maximum classification with which the word should be associated. The classification specified starts with the first non-blank character following the blank after the keyword, and continues up to the next semicolon or the end of the line. The classification can be either the short, long, or alternate name of a classification defined in the CLASSIFICATIONS: section. If the maximum classification with which a word can be associated is the classification with the highest value (as defined by the value= keyword), then there is no need to make a maxclass= keyword specification.
The maxclass= keyword must be used with extreme caution. Care must be taken if maxclass= is specified for a word to insure that the classification in a label with the word cannot be raised through combination with a label containing a higher classification. Such a combination must automatically remove the word with the maxclass. Note that both words in Appendix B, Annotated Sample Encodings with a maxclass= specification, bravo4 and charlie, are inverse words that are removed upon combination with a label with a higher classification:
The word bravo4 has a minclass and a maxclass of SECRET, and has a combination constraint that requires bravo4 to stand alone with the classification in a label. Therefore, the only valid label that can contain bravo4 is SECRET BRAVO4. Since bravo4 is associated with inverse marking bit position 12, and is the only word to use marking bit 12, the combination of any other label with SECRET BRAVO4 results in the inverse bit being forced to 1, with the net result that the bravo4 word becomes bravo2. These words are explained more fully in Appendix B, Annotated Sample Encodings.
The word charlie also has a minclass and a maxclass of SECRET, and has a combination constraint and a required combination that requires charlie to appear with alpha2 and only alpha2 in a label. Therefore, the only valid label that can contain charlie is SECRET ALPHA2 CHARLIE. Since charlie is associated with inverse marking bit position 17, and is the only word to use marking bit 17, the combination of any other label with SECRET ALPHA2 CHARLIE results in the inverse bit being forced to 1, with the net result that the charlie disappears from the label. These words are explained more fully in Appendix B, Annotated Sample Encodings.